I was having a similar problem with throat irritation and drying the first couple of days, because vaping is so different from smoking. Since you got the Ego C type I have an idea that might help you; it helped me anyway. When you are in the process of vaping if you release the power button about two thirds of the way through and keep drawing in air it dilutes and cools the vapor some which makes it less drying. This trick also completely eliminated the coughing problem you get if you try to inhale vapor like it's an analog. I think the drying and irritation are partially from the PG/VG and partially from the temperature of the vapor itself.
I started with a nice assortment of flavors and the only one I really don't like is the 'tobacco' one. Even though you smoked regular lights I highly recommend trying one of the milder peppermint flavors, like an after dinner mint one or mixing a peppermint flavor with a cream one. I never smoked menthols, and I hated the taste of them, but the peppermint ended up being my favorite flavor. The one I got is slightly cool, soothing to the throat, and it tastes like a milder form of an altoid. I love the flavor of the peppermint, but the biggest reason it's my favorite so far is that it feels the most like actualy smoking without irritating my throat at all.